You can do that by unchecking both user and guest buttons in the Captive Portal Authentication profile.
Since you are not using authentication, to simplify things make sure that "Use HTTP for Authentication" is checked and put the URL that you want users redirected to in the "Redirect URL" parameter (make sure you put http:// in front of that page):
In summary:
- Uncheck user and guest authentication in Captive Portal Authentication Profile
- Check "Use http for authentication" in Captive Portal Authentication Profile
- Change the "Redirect URL" parameter in the Captive Portal Authentication Profile to the URL you want (make sure it has http:// or https:// in front of it).
- Go to Configuration> Management > Captive Portal > Customize Login Page and upload your company's jpeg for the splash page
- The "Redirect Pause" parameter in the Captive Portal authentication profile determines how long it will stop on the jpeg splash page before being redirected to the Redirect URL.
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